The team reported two weeks ago that the first attempts at observing 2014 MU69 were unsuccessful. But in their third try, on July 17, astronomers in Argentina saw the telltale sign of MU69's presence: a stellar wink.
The third-largest object known beyond Neptune, 2007 OR10, has a moon. The discovery was reported in a poster by Gábor Marton, Csaba Kiss, and Thomas Mueller at the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society (DPS/EPSC) on Monday.
January 24 was the 30th anniversary of the Voyager flyby of Uranus. Uranian moons have been on my mind ever since New Horizons sent us close-up images of Charon. On the occasion of the anniversary, Ted Stryk produced latest-and-greatest versions of the Voyager views of these worlds.
It's looking likelier that there is an undiscovered planet orbiting beyond the Kuiper belt. If it's there, it's roughly 10 times the mass of Earth (or about half the mass of Neptune), likely never gets closer to the Sun than about 100 AU, and takes more than 10,000 years to orbit the Sun.
Pluto is reluctant to give up its secrets. Last week at the American Geophysical Union meeting I attended sessions featuring results from the New Horizons mission, and most of the presentations could be summed up thusly: the data sets are terrific, but there are still a lot of Pluto features that have scientists scratching their heads.
Last week, the pile of New Horizons LORRI camera raw image releases included nine frames from a high-resolution mosaic on Charon. Together with the color MVIC view, they make a 3D global photo of Pluto's moon. Other recently released goodies include a global backlit color image of Pluto and the first image that resolves the tiny moon Styx.
Now that New Horizons is regularly sending back data, the mission is settling into a routine of releasing a set of captioned images on Thursdays, followed by raw LORRI images on Friday. The Thursday releases give us the opportunity to see lovely color data from the spacecraft's Ralph MVIC instrument. This week, the newly available color data set covered Charon.
The New Horizons mission has formally selected its next target after Pluto: a tiny, dim, frozen world currently named 2014 MU69. The spacecraft will perform a series of four rocket firings in October and November to angle its trajectory to pass close by 2014 MU69 in early January 2019. In so doing, New Horizons will become the first flyby craft to pass by a target that was not discovered before the spacecraft launched.
It has been a difficult wait for new New Horizons images, but the wait is almost over; Alan Stern announced at today's Outer Planets Advisory Group meeting that image downlink will resume September 5. In the meantime, a few space fans are making the most of the small amount of data that has been returned to date.